Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the description correctly spends its space elsewhere. It adds real behavioral context by naming the returned fields and, importantly, clarifying that report contents are excluded and that report_url / report.note indicate readiness. It omits error behavior for a missing or invalid id.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Three tight sentences: the fetch is front-loaded, the return surface follows, and the exclusion plus the workaround (report_url, report.note) closes it. Every clause carries information an agent could act on.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description takes on the job of describing the return surface and does so concretely, including the key gotcha that report contents are not included. Only minor gaps remain, such as behavior when the id does not resolve to a check.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% and check_id is fully documented as a UUID with a format/pattern constraint. The description only restates "by its id" and adds no format, sourcing, or disambiguation detail beyond the schema, so the baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource with scoping: "Gets one reference check by its id," then enumerates exactly which fields are returned. The phrase "one ... by its id" cleanly separates it from the sibling list_* tools without needing to name them.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is implied rather than stated: an agent can infer this is the lookup-by-id path, but the description never says when to use it instead of list_recent_checks or list_completed_checks, nor mentions what to do if the id is unknown. No explicit alternatives or exclusions are given.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.